Corolla, N.C. — More than a half-dozen wild horses have been fatally shot in the Outer Banks since 2001, and authorities have posted a reward for information leading to the arrest of a gunman.

"I can't understand it at all," said Karen McCalpin, executive director of the Corolla Wild Horse Fund. "It makes me sick to think there are people out there that think nothing of killing them."

The Corolla Wild Horse fund has offered a reward of about $12,000 for information in the horse shootings.

The most recent killing occurred in late November. A black stallion was found dead in a wooded area where hunters often shoot wild hogs, and a hunter called authorities after he discovered the dead horse.

"Given the evidence and what we know about it, if I had to lean toward a conclusion, I would say it was not associated with the prior shootings," said Detective Victor Lasher, who is investigating the case for the Currituck County Sheriff's Department. "Most likely, (it) was probably an accident."

Accident or not, killing the protected wild horses is a crime.

"I just find it really hard to believe that someone could accidentally shoot a horse in that setting," McCalpin said. "It seems to me that, even if you accidentally shot the horse, you should still be held accountable for your actions because it was wrong."

Lasher said there is some physical evidence from the latest shooting, but he has little else to go on. The older shooting cases have stalled, he said.

"The other ones would be cold cases, but they're still open. By no means are we saying, 'Hey, we're done with this.' We're never going to figure it out," he said. "Somebody out there knows something, whether it be the individual that did it or somebody the individual talked to. But we need somebody to come forward and talk to us."

"My worry is the one in November is not the last one we're going to see," McCalpin said. "I just want it to stop. I just want, at some point in time, to hold somebody responsible."